# std::deque<T,Allocator>::emplace_front

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< cpp‎ | container‎ | deque

template< class... Args > void emplace_front( Args&&... args ); |  | (since C++11) (until C++17)
template< class... Args > reference emplace_front( Args&&... args ); |  | (since C++17)

Inserts a new element to the beginning of the container. The element is constructed through std::allocator_traits::construct, which typically uses placement-new to construct the element in-place at the location provided by the container. The arguments args... are forwarded to the constructor as std::forward<Args>(args)....

All iterators (including the `end()` iterator) are invalidated. No references are invalidated.

### Parameters

args | - | arguments to forward to the constructor of the element
Type requirements
- `T (the container's element type)` must meet the requirements of EmplaceConstructible.

### Return value

(none) | (until C++17)
A reference to the inserted element. | (since C++17)

### Complexity

Constant.

### Exceptions

If an exception is thrown for any reason, this function has no effect (strong exception safety guarantee).

### See also

push_front | inserts an element to the beginning (public member function)

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